Take the widest dimensions of the item you want to order and check it will fit comfortably into the space where you'd like to put it.
Tip: using masking tape, mark out the area of the furniture you'd like to buy, on the floor, to see how much space it will take up and how easily you can move around it. Check you're happy with its proportions in your room.
Step 2: Measure your home
Check the largest dimension will fit comfortably through any doors, hallways and up any stairs, without damaging paintwork or windows. If you need to carry the item through a hallway where there is no space to turn, make sure any doorways are 10cm wider than measurement A or B.
Step 3: Check your surrounding space
Make sure that you have space to walk around your new furniture. It you're buying a sofa bed or recliner, allow room for them to be extended or folded out. Reclining armchairs need about 150-180cm. For a fold-out sofa bed, you should allow about 240cm - more if you need to be able to walk around it when it's fully extended.